src: interpret the event type from the evaluation step

Postpone the event type interpretation to the evaluation step.
This patch also fixes the combination of event and object types,
which was broken. The export code needed to be adjusted too.

The new and destroy are not tokens that can be recognized by
the scanner anymore, so this also implicitly restores 'ct state'.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

4 files changed, 131 insertions, 86 deletions

diff --git a/src/evaluate.c b/src/evaluate.c
index 602148c8..83ef7498 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -59,6 +59,8 @@ static int __fmtstring(4, 5) __stmt_binary_error(struct eval_ctx *ctx,
 	__stmt_binary_error(ctx, &(s1)->location, &(s2)->location, fmt, ## args)
 #define chain_error(ctx, s1, fmt, args...) \
 	__stmt_binary_error(ctx, &(s1)->location, NULL, fmt, ## args)
+#define monitor_error(ctx, s1, fmt, args...) \
+	__stmt_binary_error(ctx, &(s1)->location, NULL, fmt, ## args)
 
 static int __fmtstring(3, 4) set_error(struct eval_ctx *ctx,
 				       const struct set *set,
@@ -1610,6 +1612,72 @@ static int cmd_evaluate_delete(struct eval_ctx *ctx, struct cmd *cmd)
 	}
 }
 
+enum {
+	CMD_MONITOR_EVENT_ANY,
+	CMD_MONITOR_EVENT_NEW,
+	CMD_MONITOR_EVENT_DEL,
+	CMD_MONITOR_EVENT_MAX
+};
+
+static uint32_t monitor_flags[CMD_MONITOR_EVENT_MAX][CMD_MONITOR_OBJ_MAX] = {
+	[CMD_MONITOR_EVENT_ANY] = {
+		[CMD_MONITOR_OBJ_ANY]		= 0xffffffff,
+		[CMD_MONITOR_OBJ_TABLES]	= (1 << NFT_MSG_NEWTABLE) |
+						  (1 << NFT_MSG_DELTABLE),
+		[CMD_MONITOR_OBJ_CHAINS]	= (1 << NFT_MSG_NEWCHAIN) |
+						  (1 << NFT_MSG_DELCHAIN),
+		[CMD_MONITOR_OBJ_RULES]		= (1 << NFT_MSG_NEWRULE) |
+						  (1 << NFT_MSG_DELRULE),
+		[CMD_MONITOR_OBJ_SETS]		= (1 << NFT_MSG_NEWSET) |
+						  (1 << NFT_MSG_DELSET),
+		[CMD_MONITOR_OBJ_ELEMS]		= (1 << NFT_MSG_NEWSETELEM) |
+						  (1 << NFT_MSG_DELSETELEM),
+	},
+	[CMD_MONITOR_EVENT_NEW] = {
+		[CMD_MONITOR_OBJ_ANY]		= (1 << NFT_MSG_NEWTABLE) |
+						  (1 << NFT_MSG_NEWCHAIN) |
+						  (1 << NFT_MSG_NEWRULE)  |
+						  (1 << NFT_MSG_NEWSET)   |
+						  (1 << NFT_MSG_NEWSETELEM),
+		[CMD_MONITOR_OBJ_TABLES]	= (1 << NFT_MSG_NEWTABLE),
+		[CMD_MONITOR_OBJ_CHAINS]	= (1 << NFT_MSG_NEWCHAIN),
+		[CMD_MONITOR_OBJ_RULES]		= (1 << NFT_MSG_NEWRULE),
+		[CMD_MONITOR_OBJ_SETS]		= (1 << NFT_MSG_NEWSET),
+		[CMD_MONITOR_OBJ_ELEMS]		= (1 << NFT_MSG_NEWSETELEM),
+	},
+	[CMD_MONITOR_EVENT_DEL] = {
+		[CMD_MONITOR_OBJ_ANY]		= (1 << NFT_MSG_DELTABLE) |
+						  (1 << NFT_MSG_DELCHAIN) |
+						  (1 << NFT_MSG_DELRULE)  |
+						  (1 << NFT_MSG_DELSET)   |
+						  (1 << NFT_MSG_DELSETELEM),
+		[CMD_MONITOR_OBJ_TABLES]	= (1 << NFT_MSG_DELTABLE),
+		[CMD_MONITOR_OBJ_CHAINS]	= (1 << NFT_MSG_DELCHAIN),
+		[CMD_MONITOR_OBJ_RULES]		= (1 << NFT_MSG_DELRULE),
+		[CMD_MONITOR_OBJ_SETS]		= (1 << NFT_MSG_DELSET),
+		[CMD_MONITOR_OBJ_ELEMS]		= (1 << NFT_MSG_DELSETELEM),
+	},
+};
+
+static int cmd_evaluate_monitor(struct eval_ctx *ctx, struct cmd *cmd)
+{
+	uint32_t event;
+
+	if (cmd->monitor->event == NULL)
+		event = CMD_MONITOR_EVENT_ANY;
+	else if (strcmp(cmd->monitor->event, "new") == 0)
+		event = CMD_MONITOR_EVENT_NEW;
+	else if (strcmp(cmd->monitor->event, "destroy") == 0)
+		event = CMD_MONITOR_EVENT_DEL;
+	else {
+		return monitor_error(ctx, cmd->monitor, "invalid event %s",
+				     cmd->monitor->event);
+	}
+
+	cmd->monitor->flags = monitor_flags[event][cmd->monitor->type];
+	return 0;
+}
+
 int cmd_evaluate(struct eval_ctx *ctx, struct cmd *cmd)
 {
 #ifdef DEBUG
@@ -1632,9 +1700,10 @@ int cmd_evaluate(struct eval_ctx *ctx, struct cmd *cmd)
 	case CMD_FLUSH:
 	case CMD_RENAME:
 	case CMD_EXPORT:
-	case CMD_MONITOR:
 	case CMD_DESCRIBE:
 		return 0;
+	case CMD_MONITOR:
+		return cmd_evaluate_monitor(ctx, cmd);
 	default:
 		BUG("invalid command operation %u\n", cmd->op);
 	};
diff --git a/src/parser.y b/src/parser.y
index aac25679..e813b258 100644
--- a/src/parser.y
+++ b/src/parser.y
@@ -198,9 +198,6 @@ static void location_update(struct location *loc, struct location *rhs, int n)
 %token GOTO			"goto"
 %token RETURN			"return"
 
-%token NEW			"new"
-%token DESTROY			"destroy"
-
 %token CONSTANT			"constant"
 %token INTERVAL			"interval"
 %token ELEMENTS			"elements"
@@ -532,7 +529,9 @@ static void location_update(struct location *loc, struct location *rhs, int n)
 %type <val>			ct_key
 
 %type <val>			export_format
-%type <val>			monitor_event	monitor_object		monitor_format
+%type <string>			monitor_event
+%destructor { xfree($$); }	monitor_event
+%type <val>			monitor_object	monitor_format
 
 %%
 
@@ -798,89 +797,30 @@ rename_cmd		:	CHAIN		chain_spec	identifier
 export_cmd		:	export_format
 			{
 				struct handle h = { .family = NFPROTO_UNSPEC };
-				$$ = cmd_alloc(CMD_EXPORT, CMD_OBJ_RULESET, &h, &@$, NULL);
-				$$->format = $1;
+				struct export *export = export_alloc($1);
+				$$ = cmd_alloc(CMD_EXPORT, CMD_OBJ_EXPORT, &h, &@$, export);
 			}
 			;
 
 monitor_cmd		:	monitor_event	monitor_object	monitor_format
 			{
 				struct handle h = { .family = NFPROTO_UNSPEC };
-				$$ = cmd_alloc(CMD_MONITOR, CMD_OBJ_RULESET, &h, &@$, NULL);
-				$$->monitor_flags = $1 & $2;
-				$$->format = $3;
+				struct monitor *m = monitor_alloc($3, $2, $1);
+				m->location = @1;
+				$$ = cmd_alloc(CMD_MONITOR, CMD_OBJ_MONITOR, &h, &@$, m);
 			}
 			;
 
-monitor_event		:	/* empty */
-			{
-				$$ = (1 << NFT_MSG_NEWRULE)	|
-				     (1 << NFT_MSG_DELRULE)	|
-				     (1 << NFT_MSG_NEWSET)	|
-				     (1 << NFT_MSG_DELSET)	|
-				     (1 << NFT_MSG_NEWSETELEM)	|
-				     (1 << NFT_MSG_DELSETELEM)	|
-				     (1 << NFT_MSG_NEWCHAIN)	|
-				     (1 << NFT_MSG_DELCHAIN)	|
-				     (1 << NFT_MSG_NEWTABLE)	|
-				     (1 << NFT_MSG_DELTABLE);
-			}
-			|	NEW
-			{
-				$$ = (1 << NFT_MSG_NEWTABLE)	|
-				     (1 << NFT_MSG_NEWCHAIN)	|
-				     (1 << NFT_MSG_NEWRULE)	|
-				     (1 << NFT_MSG_NEWSET)	|
-				     (1 << NFT_MSG_NEWSETELEM);
-			}
-			|	DESTROY
-			{
-				$$ = (1 << NFT_MSG_DELTABLE)	|
-				     (1 << NFT_MSG_DELCHAIN)	|
-				     (1 << NFT_MSG_DELRULE)	|
-				     (1 << NFT_MSG_DELSET)	|
-				     (1 << NFT_MSG_DELSETELEM);
-			}
+monitor_event		:	/* empty */	{ $$ = NULL; }
+			|       STRING		{ $$ = $1; }
 			;
 
-monitor_object		:	/* empty */
-			{
-				$$ = (1 << NFT_MSG_NEWRULE)	|
-				     (1 << NFT_MSG_DELRULE)	|
-				     (1 << NFT_MSG_NEWSET)	|
-				     (1 << NFT_MSG_DELSET)	|
-				     (1 << NFT_MSG_NEWSETELEM)	|
-				     (1 << NFT_MSG_DELSETELEM)	|
-				     (1 << NFT_MSG_NEWCHAIN)	|
-				     (1 << NFT_MSG_DELCHAIN)	|
-				     (1 << NFT_MSG_NEWTABLE)	|
-				     (1 << NFT_MSG_DELTABLE);
-			}
-			|	TABLES
-			{
-				$$ = (1 << NFT_MSG_NEWTABLE) |
-				     (1 << NFT_MSG_DELTABLE);
-			}
-			|	CHAINS
-			{
-				$$ = (1 << NFT_MSG_NEWCHAIN) |
-				     (1 << NFT_MSG_DELCHAIN);
-			}
-			|	SETS
-			{
-				$$ = (1 << NFT_MSG_NEWSET) |
-				     (1 << NFT_MSG_DELSET);
-			}
-			|	RULES
-			{
-				$$ = (1 << NFT_MSG_NEWRULE) |
-				     (1 << NFT_MSG_DELRULE);
-			}
-			|	ELEMENTS
-			{
-				$$ = (1 << NFT_MSG_NEWSETELEM) |
-				     (1 << NFT_MSG_DELSETELEM);
-			}
+monitor_object		:	/* empty */	{ $$ = CMD_MONITOR_OBJ_ANY; }
+			| 	TABLES		{ $$ = CMD_MONITOR_OBJ_TABLES; }
+			| 	CHAINS		{ $$ = CMD_MONITOR_OBJ_CHAINS; }
+			| 	SETS		{ $$ = CMD_MONITOR_OBJ_SETS; }
+			|	RULES		{ $$ = CMD_MONITOR_OBJ_RULES; }
+			|	ELEMENTS	{ $$ = CMD_MONITOR_OBJ_ELEMS; }
 			;
 
 monitor_format		:	/* empty */	{ $$ = NFT_OUTPUT_DEFAULT; }
diff --git a/src/rule.c b/src/rule.c
index 43355eeb..a79a4203 100644
--- a/src/rule.c
+++ b/src/rule.c
@@ -556,6 +556,39 @@ struct cmd *cmd_alloc(enum cmd_ops op, enum cmd_obj obj,
 	return cmd;
 }
 
+struct export *export_alloc(uint32_t format)
+{
+	struct export *export;
+
+	export = xmalloc(sizeof(struct export));
+	export->format = format;
+
+	return export;
+}
+
+void export_free(struct export *e)
+{
+	xfree(e);
+}
+
+struct monitor *monitor_alloc(uint32_t format, uint32_t type, const char *event)
+{
+	struct monitor *mon;
+
+	mon = xmalloc(sizeof(struct monitor));
+	mon->format = format;
+	mon->type = type;
+	mon->event = event;
+	mon->flags = 0;
+
+	return mon;
+}
+
+void monitor_free(struct monitor *m)
+{
+	xfree(m);
+}
+
 void cmd_free(struct cmd *cmd)
 {
 	handle_free(&cmd->handle);
@@ -579,6 +612,12 @@ void cmd_free(struct cmd *cmd)
 		case CMD_OBJ_EXPR:
 			expr_free(cmd->expr);
 			break;
+		case CMD_OBJ_MONITOR:
+			monitor_free(cmd->monitor);
+			break;
+		case CMD_OBJ_EXPORT:
+			export_free(cmd->export);
+			break;
 		default:
 			BUG("invalid command object type %u\n", cmd->obj);
 		}
@@ -726,7 +765,7 @@ static int do_command_export(struct netlink_ctx *ctx, struct cmd *cmd)
 	if (rs == NULL)
 		return -1;
 
-	nft_ruleset_fprintf(stdout, rs, cmd->format, 0);
+	nft_ruleset_fprintf(stdout, rs, cmd->export->format, 0);
 	fprintf(stdout, "\n");
 
 	nft_ruleset_free(rs);
@@ -929,9 +968,9 @@ static int do_command_monitor(struct netlink_ctx *ctx, struct cmd *cmd)
 	 *  - new rules in default format
 	 *  - new elements
 	 */
-	if (((cmd->monitor_flags & (1 << NFT_MSG_NEWRULE)) &&
-	    (cmd->format == NFT_OUTPUT_DEFAULT)) ||
-	    (cmd->monitor_flags & (1 << NFT_MSG_NEWSETELEM)))
+	if (((cmd->monitor->flags & (1 << NFT_MSG_NEWRULE)) &&
+	    (cmd->monitor->format == NFT_OUTPUT_DEFAULT)) ||
+	    (cmd->monitor->flags & (1 << NFT_MSG_NEWSETELEM)))
 		monhandler.cache_needed = true;
 	else
 		monhandler.cache_needed = false;
@@ -963,8 +1002,8 @@ static int do_command_monitor(struct netlink_ctx *ctx, struct cmd *cmd)
 		}
 	}
 
-	monhandler.monitor_flags = cmd->monitor_flags;
-	monhandler.format = cmd->format;
+	monhandler.monitor_flags = cmd->monitor->flags;
+	monhandler.format = cmd->monitor->format;
 	monhandler.ctx = ctx;
 	monhandler.loc = &cmd->location;
 
diff --git a/src/scanner.l b/src/scanner.l
index 0955c4af..b5d7d4f9 100644
--- a/src/scanner.l
+++ b/src/scanner.l
@@ -261,9 +261,6 @@ addrstring	({macaddr}|{ip4addr}|{ip6addr})
 "export"		{ return EXPORT; }
 "monitor"		{ return MONITOR; }
 
-"new"			{ return NEW; }
-"destroy"		{ return DESTROY; }
-
 "position"		{ return POSITION; }
 "comment"		{ return COMMENT; }